Claude Opus 4.8 vs GLM-5.3 — Price, Context, and Capability Compared
Claude Opus 4.8 vs GLM-5.3: which should I use?
Claude Opus 4.8 costs 4.7× more per blended million tokens than GLM-5.3. GLM-5.3 has the larger context window (1,000,000 tokens). Default to GLM-5.3 unless you specifically need Claude Opus 4.8's edge.
Where can you find price, speed, and task evidence for Claude Opus 4.8 and GLM-5.3?
Which tasks fit Claude Opus 4.8 and GLM-5.3?
Best-fit task signals from the published model strengths; this is not a substitute for a controlled benchmark.
| Fact | Claude Opus 4.8 | GLM-5.3 |
|---|---|---|
| Best fit | Complex, multi-step tasks where Fable 5’s premium isn’t justified. | Long-horizon coding on open weights at a fraction of frontier pricing. |
| Reasoning mode | Available | Available |
What does a Coding Agent workload cost with Claude Opus 4.8 and GLM-5.3?
Modeled for Coding Agent: 20,000 input + 2,000 output tokens per task, 1 turn. This is a workload model, not a provider quote.
| Fact | Claude Opus 4.8 | GLM-5.3 |
|---|---|---|
| Coding Agent / task | $0.15 (modeled) | $0.04 (modeled) (winner) |
| Input / output rate | $5.00 / $25.00 per M | $1.40 / $4.40 per M |
How fast are Claude Opus 4.8 and GLM-5.3?
Only non-estimated benchmark results are shown as measured.
| Fact | Claude Opus 4.8 | GLM-5.3 |
|---|---|---|
| Measured throughput | 58 tokens/s | Unavailable |
| Time to first token | 470 ms | Unavailable |
How compatible are Claude Opus 4.8 and GLM-5.3 with APIs?
Provider-level wire-format and SDK facts; model-specific parameter differences may still apply.
| Fact | Claude Opus 4.8 | GLM-5.3 |
|---|---|---|
| OpenAI SDK | Not drop-in | Usable |
| Request shape | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. | OpenAI-compatible chat/completions endpoint at api.z.ai/api/paas/v4. |
| Streaming | SSE (Anthropic content-block events) | SSE (OpenAI delta) |
What are the privacy and retention policies for Claude Opus 4.8 and GLM-5.3?
Provider policy and residency facts from the verified provider registry. A missing retention policy is not treated as a guarantee.
| Fact | Claude Opus 4.8 | GLM-5.3 |
|---|---|---|
| Provider says API data trains models | No | Unavailable |
| Published retention period | Unavailable | Unavailable |
| Data residency | Unavailable | Unavailable |
How much effort does it take to migrate between Claude Opus 4.8 and GLM-5.3?
Direction is from each displayed model to the other. Effort is derived from provider compatibility and published parameter maps.
| Fact | Claude Opus 4.8 | GLM-5.3 |
|---|---|---|
| Move Claude Opus 4.8 → GLM-5.3 | config; 2 breaking parameter differences | Target: GLM-5.3 |
| Move GLM-5.3 → Claude Opus 4.8 | Source: GLM-5.3 | code-change; 3 breaking parameter differences |
| Why | Keep the `openai` SDK; change `baseURL` and the API key. | Messages API — system prompt is a top-level field, not a message role, and max_tokens is required on every call. |
How do Claude Opus 4.8 and GLM-5.3 compare on specs?
| Claude Opus 4.8 | GLM-5.3 | |
|---|---|---|
| Price (input) | $5.00/M | $1.40/M ✓ |
| Price (output) | $25.00/M | $4.40/M ✓ |
| Blended price | $10.00/M | $2.15/M ✓ |
| Context window | 500,000 tokens | 1,000,000 tokens ✓ |
| Max output | 64,000 tokens | 131,072 tokens ✓ |
| Modalities | text, vision | text |
| Reasoning mode | Yes | Yes |
| Released | 2026-04 | 2026-08 |
| Speed | 58 t/s | Not measured |
How much do Claude Opus 4.8 and GLM-5.3 cost at scale?
| Tokens / month | Claude Opus 4.8 | GLM-5.3 | Delta |
|---|---|---|---|
| 1,000,000 | $10.00 | $2.15 | $7.85 (4.7×) |
| 10,000,000 | $100.00 | $21.50 | $78.50 (4.7×) |
| 100,000,000 | $1000.00 | $215.00 | $785.00 (4.7×) |
Choose Claude Opus 4.8 if…
- ✓Elite coding and multi-step reasoning
- ✓Strong instruction following on ambiguous prompts
- ✓Extended-thinking mode
- ✓Complex, multi-step tasks where Fable 5’s premium isn’t justified.
Choose GLM-5.3 if…
- ✓Z.ai coding-first flagship, 50% stronger than 5.2 on code bench
- ✓1M-token context with 128K outputs
- ✓Mandatory reasoning with low/high/max effort
- ✓Long-horizon coding on open weights at a fraction of frontier pricing.
Run this exact matchup right now
Send the same prompt to Claude Opus 4.8 and GLM-5.3 side by side and see the outputs yourself.
Try Claude Opus 4.8 vs GLM-5.3 FreeWhat are common questions about Claude Opus 4.8 and GLM-5.3?
Is Claude Opus 4.8 cheaper than GLM-5.3?
GLM-5.3 is cheaper, at $2.15 per million blended tokens vs $10.00 for Claude Opus 4.8.
Which has the bigger context window, Claude Opus 4.8 or GLM-5.3?
GLM-5.3 has the larger context window: 1,000,000 tokens vs 500,000.
Can Claude Opus 4.8 replace GLM-5.3 for coding?
Both are viable for coding. Elite coding and multi-step reasoning (Claude Opus 4.8) vs Z.ai coding-first flagship, 50% stronger than 5.2 on code bench (GLM-5.3) — pick based on which strength matters more for your workload.
Neither of these? See Claude Opus 4.8 alternatives or GLM-5.3 alternatives.
What related comparisons help choose between Claude Opus 4.8 and GLM-5.3?
Pricing verified 2026-06-07. Specs verified 2026-08-14.